Engine starter meshing means



i atented July 24, 1951 1" UNITED STATES "OFFICE r 1 v 2,561,9 ibj7f' i ENGINE STARTER I signor to Bendix AviationCorporation, boro, N. J a corporationlo'f Delaware Teter- V Original application Novembe'r13, 1947, Serial No.

7 1950, Serial No. 161,778,

4 Claims. (Cl. 123-179) This application is a division of application Serial No. Patent No. 2,548,268, and relates to engine starter's, andparticularly to a starter of the self-contained high-speed type, in which the turning motion is transmitted'through a rotatable output with the axis of rotationof an'engine member. Among the objects of the invention are to provide a starter. structure or system of greatly in-' creased power and reduced weight as for aircraft 785,123, filed November 13, 194'1, now

member or jaw having its axisof rotation inlin'e service and which shall avoid the disadvantages of overrunning'clutches; such as destruction of parts by centrifugal'forc'e upon failure of op-' eration, completely separate the high speed meshing starter and engine members, reduce .critical'tolerances, mesh the starter and engine axially biased together, as

members prior'to a given rate of operation of the starter, and have other advantages. f Another object is to provide a device of the above-indicated character which shallbesimple and durable in construction, facture, and effective in its operation. I The above and'other objects'andffeaturesjof the invention willfappear more fully hereinafter from a consideration of the accompanying draiwings wherein one embodiment of the invention is illustrated byway of example. v In the drawing, the single figure is a diagram of asystem includinga view in section of a starter of the invention. 1 The device comprises a rotatableengine-em gaging member I0 adapted for axial etxension from and a position meshed with an engine member (not shown) for starting the engine. The further comprises an axially stationary device rotative 'nut ,I8 adapted .to rotate the nut I4, a screw shaft element 20 axially movable relative to, and rotatively movable by, the nut 14 associated with the engine-engaging member I0 for rotating the latter. The screw shaft element 20 is adapted to move the engine-engaging member I0 in its axial extension movement engaging it to the engine member.- a p Means including spring means 26 cooperate with the meshing rod 22 to oppose movement of the member I0 by the screw shaft 20. Means 28 are also adapted to effect the movement of the screw shaft element 20 through the intermediary of a yieldable medium, which in this case is compressed air. Means 34 provide for first initiating movement of the screw lowing with rotative action of the engine-engaging member I0 by the driving means l8.

The driving means IBIcomprises a plate I50 adapted for attachment to the rotor of a turbine I4, means including driving means economical to manushaft element 20 and fol-- Divided and thisapplication June .13,

2 or other. motor (not shown), and provided wth a female spline extension I52 adapted torec'eive a cooperating male spline shaft I54, journaled by a bearing l56 in an end plate I58of a housing 38. v The plate I50 is held axially relative ;to tl e shaft I54 between the bearing I56 and a nut structure I60 in a cavity of the extensionl52,

A portion I62 of the housing 38 has a chamber- I64 in whichis disposed a flange I66of theshaft I54 which is secured, as by a ring I68 and screws I10, to a closed end wall I12 of a barrel I14 jour naled in the housing portion I62 as by bearings I16.

The spline nut I4, in the barrel I14, is connects ed to the latter by a torquelimiting frict on disc pack I16 having interlayered discs fixed to the, nut I4 and the barrel I14, respectively, and; by helical springs I and a ring nut I82 threaded in the oppositeend; of the barrel I14. I

The screw shaft 20, having long-leadthread relation to the nutI4 therein, ,has an axially; slidable spline connection I84 to the starter clutch jaw member I0. 1

The jaw III and the screw shaft 20 are con;-; nected by the meshing rod 22 having a head..I86 and extending through an aperture in the jawIIl; which ap-ertureis closed by a seal MIL-biased against'the jaw by a spring I extending into the screw shaft 20. the rod 22 at the left of the jaw I0.

The screw shaft 20 is limited in its axial move-. ment to the right; as viewed in the drawingby engagementwith a disc I92 against the barrel end wall I12 and, in its axial movement to the left bya usual shoulder on the screw shaftv20 with a shoulder on the spline nut I4. A ring seal structure I94, not-germane to the present invention, cooperatesbetween a bafile portion I96-of the housing 38 and the jaw member I0. H 1

The screw shaft 20, instead of being for advancement by'rotation of the nut I4 as in a usual direct-cranking starter having friction meansads jacent to the seal I94, the latter of which isnot true in this case, is adapted as by seal rings! I98 and 200 in'groove's of the screwshaft around the rod 22 and the shaft 20, respectively for action as a piston responsive to fluid pressure :in troduces into the chamber I64. V i

An inlet 202 admits fluid to the chamber I64for' passage, indicated'by arrows, through passage ways 204, 206 and 208, see lower central portion of the figure, to the screw-shaft-piston20.

The means 28 comprises an electrical unit 2") having a plunger I34 which has'its lower-end constructed as the movable element of a valve 2 I 2 for controlling the flow of fluid, such-as 'com A nut I9I is mounted on pressed air, form a source 2 I4 through a pipe 2 I B, the valve 2I2 and a pipe 2! to the inlet 202. The unit 2I0 includes a solenoid coil I30 surrounding a hollow armature core 1.32 carrying the plunger 134 axially movable relative thereto. The plunger 34 has a head I36 normally held against a seat I 38 of the core in turn is hacked and ing ring I40 positioned in a groove of the core I 32. Downward movement of the core I 32, as shown, is limited by stop-means I42. Spring contacts I43, movably carried by the plunger I34, constitutes a bridging contact member. tionary contact motor 220.

Means 34 provide for first initiating the axial elements .I44-to energize the I32 by a spring 32, which 7 held inplace .by a lockfor -staextension movement of the screw shaft element 20, during which, priorto rotation of the shaft 1'54; the element will rotate, but not 'under'the power of the shaft I54.

device 220 corresponds either to a motor or another electrical unit for starting a turbine and is controlled as by aswitch 92 relative to a source o'f'electromotive force 90.

In' "operation, with the parts in the inactive positions shown, when the switch 92 is closed, current flows "from one side of the source 90 through a conductor 222, the switch 92, the solenoid coil I30 'of the unit 2I0, and a conductor 224 to the opposite side of the source 90. This action first opens the valve 2I2 to cause flow of fluid from the source 214 through the pipe 2I6,

thevalve'2I2 and the pipe 218 to the inlet 202,

and into the chamber I64. From the latter, the fluid flows, as indicated by arrows, through the passageways 204, 206 and 208 to the rear of the piston screw shaft 20 to-advance the latter to the left and to push the member I0 through the intermediaryof th spring means :I80 into engagement with the engine member, during which the shaft 20 will rotate in the stationary unit I4 :to rotate the member I0. The timing oftheopening of the valve 2I2 and the closing of the circuit 0f the device 200 is, in this instance, such that the shaft piston 20 will cause the rotating member I0 to :engage the engine :member before driving operation of the shaft I54. Thus, the

member I0 has achanceto mesh before the application of rotative power. If, however, butting should occur, meshing will be insured :upon the first application of rotative driving power prior to :the attainment of a certain .rate of speed byithe member ID.

:Thetiming aforesaid may be varied such that power rotation may be applied upon or at any time before :or after engagement of the member I0 with the engine :member as desired or dependent upon conditions of, or circumstances surrounding a particular case.

.Thedevice has an advantage ,over other forms of .meshing in that it utilizes standard parts :of former starters not previously operable in the Same manner. The invention therefore ,provides for a very reat range of its application and uses, and is an improvement generally in its field.

Although only one embodiment of the invention has been illustrated and described various changes in the :form and relative arrangement of the parts may be made to suit requirements.

What .is claimed is:

1,. .In an engine startingmechanism, the combination -of a rotatable engine-engaging member 5 ling thelcircuit with the engine-engaging member for rotating in its said axial extension movement, means including spring means cooperating with said rod element for opposing said extension movement of the engineeengaging member, means for effect- 'ing-saidpress;ure, means responsive to the operation of saidpressure efiecting means for controlof said motor; and means adapted to actuate said pressure efiecting means to operate said rod element to-efiectsaid extension movement @and said ,cir.cuit controlling means to Lenergize the motor. Y

2. In an engine starting mechanism, theconl bination of a rotatable engine-engaging member adapted ,for axial extension and retraction movements, respectively, between a position released from and a position meshed withan engine element for starting the engine, an axially stationary rotative nut, driving means adapted torotate the nut,,a screw shaft element axially movable relative to and rotativelyfmovable .by the nut and associated with the engine-engaging member for rotating the latter, a .meshin'g rod element, said meshing .rod element being adapted to move saidengine-engaging.memberfin its said axial extension movement engaging it to said en gine element, spring means cooperating with said meshing rod element to oppose said movement of the engine-engaging member by said meshing rod element; a ,first power means including ,a source of fluid pressure toac'tuate said meshing rod element, and a second independent power means to effect rotation of said nut throughsaid driving'means, and control means operated by said first ,p'ower means for initiatingioperation of said second power means and rotative action of said engine-engaging member by said driving meansfollowing initiation of the axial extension movement of the engine-engaging member "by said first powermeans so that complete meshing of the engine-engaging member with the engine element is accomplished.

13. The combinationdefined by claim'2in which said control means'includes'a solenoid, a valve'to control said source of'fiuid pressure, and a switch operated "by the solenoid to initiate operation of said second power'means." p 4. The combination ,defined by claim'2 in-which said control means includes a-solenoid operated valve to control said source of fluid 'pressuraand means responsive to operation of said valve to initiate operation of said second powe'r-means.

CHARLES 'S. 'METSGER.

REFERENCES CITED I The following referencesare of record in the file of this patent:

UNITED .STATES PATENTS Number Name Date 1,833,948 Lansing Dec. '1, 1931 2,301,440 Nardone Nov. 10, 1942 FOREIGN PATENTS Number Country Date 515,753 .Great Britain Dec. .13, 1939 

